Insulator



Aug. 2. 1927. 6 9

c. AALBORG msunuon Filed March 15, 1922 QINVENTOR WIT E SE U/zglsfihn 5mm ATTORNEY Patented Aug. 2, 1927.

UNITED STATES PATENTFOFFICEI;

CHRISTIAN AALBORG, or PITTSBURGH, PENNSYLVANIA, ASSIGNOR 'ro WESTING- nousn ELECTRIC & MANUFACTURING COMPANY, A CORPORATION or rn NsYre VANIA.

INSULATOR.

Application filed March 15, 1922. Serial No. 548,908.

My invention relates to insulators and particularly to insulators of the link type.

' One object of my invention is to provlde an insulator, ofthe above indicated character, that shall so resolve longitudinal load forces into lateral components as to -materially increase the mechanical strength thereof. l V

Another. object of my invention 18 to pro vide an insulator of the link type that shall have increased surface resistance and decreased weight for a given difference of potential between the terminals thereof.

Another object of my invention is to provide an insulator of the link type that shall be so constructed as a solid of revolution as to readily adaptit to any one of a wide variety of circuit voltages by the simple expedient of varying its length.

Another object of my invention is to provide a link-type insulator of such shape as to facilitate its being constructed of porcelain or other refractory material and that shall. so comprise balanced masses or properly proportional partsas to ensure against the occurrence of defects during its manufacture'. 4

Another object of-my invention is to provide an insulator of the link type in which the terminal or linked connector members shall be so doubly linked as to strengthen, and 'to more widely distribute stresses in, the insulating member.

In insulators of the link type, it has heretofore been usual to provide an insulating body member having interlinked reentrant openings of substantially U-shape for thereception of terminal members of similar shape. Such insulators have been successfully, employed in low-voltage 'SGIVICB, in which the insulating body has been of small mass and of simple block construction.

However, in higlrvoltage service where insulators of the link type are provided with petticoats, difficulties arise in the manufacture of the porcelain bodies which entail much care and precision in the proportioning of the parts. In fact, unless the quality and proportions of the porcelain mass are very exact and the shaping, firing and glazing thereof performed with great care, defects which render the insulator useless are very likely to occur. These difiiculties have been caused by the peculiar shape of the insulator in which a relatively thick central mass has been surrounded by a relatively thin petticoat portion. A r

-The above mentioned features have naturally limited'the size of link insulators and .reduced the scope of service for whichthey are adapted. To adapt them to voltages of diii erent ratings has usually entailed changes in the whole mass of insulating material.

That is, they have beenmade larger or smaller, in substantially all dimensions, in accordance with the voltages which they were adapted to withstand. This 1 feature occasioned theuseof many'diiferent molds.

Further, by reason of the shapes of the.

terminal members,-which are usually cables or rods interlinkingeach other at right an gles, the main load forces are nearly all 0011-. centrated in the longitudinal planes ofthe intersecting loops. I In practicing my inventioin l provide an insulating member, of refractory or other insulating material, that is a simple solid of revolution, symmetrical in all of its parts and in which the masses are so related as to reduce the likelihood of defects during manufacture. Substantially straight openings, of easy formation, are provided for the re ception of the terminal ine'mbers'which' are so iuterlinked'in substantially square-knot formation," and so adapted to resolve the longitudinal load forces into lateral components, as to greatly increase the mechanical strength of the insulator. Further, by reaformation of relatively large petticoats of anydesired number, to thereby increase the surface resistance, and reduce the weight, of

the insulator for a given voltage.

Figure 1, of the accompanying drawings, is a side View ofan insulator andbonnecting members einhodying my invention.

Fig. 2 is a view similar to Fig. 1, taken at right angles thereto, and" Figs. 3, 4t and 5 areviews, similar to Fig;

1, but on a smaller scale, of insulators embodying modified formsiof my invention.-

As shown in Fi 1 and 2, an insulatin member 1, preferaEl of porcelain, is forme as a simple solid of revolution that is provided with a cylindrical body portion 2 and lateral] extending discoidal petticoat or projecting portions 3 having perimetral grooves 4 therebetween.

At each end of the body portion 2, a pair of openin 5, the entrances of which register longitudinally opposite the entrances to the corresponding openings at the opposite end of the insulator, are sloped, in parallel relation from the entrances thereof and through the central bodyportion 2, to positions intercepting the farthermost roove 4. These openings extend beneath t e inner surface of the yo 4 that is nearest to the end at the-openings enter.

An insulator of the above described oonstrnotionpermits terminal or connector members fi, preferably of flexible or pliable metal construction, to be threaded through the cam s5 and around the body portion 2, s lall in the form of a square or root knot having-closed-end or loop portions 7 at right angles to the remainder of the conmotors and doubly interlinked with each other. 1

Theconstruction provides substantially double the direct compression area between the connector loops, which area is angularly rotated to the compression area in a usual link insulatorto thus resolve the longitudina'l load forces in the terminal members 6 into a lateral component, as indicated by arrows 8 in Fig. 1. By reason of the relation of the sloped openings 5 to the entrances thereof, the longitudinal load forces are further resolved into lateral components at the ends of the insulator, as indicated by arrows 9 in Fig. 1.

The forces being thus subdivided or dis- I tributed, permit the insulator to be of smaller volume and,-therefore, more easily fired.

The general arrangement of parts provides an insulator of easy manufacture and 1 of great strength, that is of increased surface resistance and of reduced weight for a given voltage between its ends.

As shown in Fig. 4, in which similar parts are designated by similar reference numerals, a modified form of my invention comprises an insulator similar to that of the above-descrihed form, with the exception of the number of the petticoats 3 and the grou ing thereof relative to the terminal mem rs 6. This form of insulator illustrates the manner of adapting the same for voltages of widely different values by merely making it longer or shorter. Thus, a relatively long body member, of uniform lateral dimensions, may be cut or divided into insulators of any desired length to greatly facilitate the construction of insulators of widely different voltage-resisting values by a simple molding, turning or other manufacturing operation.

As shown in Figs. 3 and 5, the laterally projecting portions 3 may be variously modified as to shape and dimensions, the form shown in Fig. 3 having the end portions 3 narrower but thicker, or otherwise shaped, to provide sufiicient surfaceresistance, and the form shown in Fig. 5 bovin an elongated laterally-reduced intermediate portion '3.

While-I have shown and described particular forms of my invention, various changes in the construction, shape and relation of parts may be effected therein without departing from the spirit and scope thereof, as set forth in the appended claims.

I claim as my invention:

L In an insulator, the combination with an insulating structure comprising a plurality of laterally projecting portions and a. reduced portion between said projectin portions, of a terminal connector for one on of the insulator comprising a portion embracing a portion of said reduced portion and longitudinally extending portions pro jecting from said embracing portion through openings in the insulator tosaid end.

2. In an insulator, the condiination with an insulating structure having longitudinally spaced perimetral grooves and openings extending from each end of the structure to one of said grooves, of a terminal structure for each of the insulator comprising a portion embracing a portion of said insulating structure in one of said grooves and portions projecting from said embracing portion through said openings to the same end of the insulator.

3. An insulator comprising a body memher having a plurality of longitudinally spaced laterally projecting ortions and openings extending from eac end of the member to .a space between said laterally projecting portions closer to the other end of the member than the space to which the openings from the other end extend.

4. In an insulator, the combination with an insulatin member comprising a plurality of latera y projecting rtions and reduced portions between sai projectin portions, of a terminal connector for eac of the insulator comprising a looped member disposed in openings in said insulating member and extending partially around one of said reduced portions.

5. In an insulator, the combination with an insulating member having longitudinally spaced ,per'imetral grooves and openings extending from each end of the member .to one of said grooves, of a terminal member .at each end of the insulator comprising an elongated member extending continuously from endthrough the other opening at the sameend between the lateral'ly projecting portions of the insulator. thereof.

6. An insulator of the link type compris- In testimony whereof, I have hereunto ing an elongated body member havin a piusubscribed my name this 10th day of March, 5 rality of longitudinally spaced latera 1y pro- 1922.

jecting portions and openings extending from the ends of the member to the spaces CHRISTIAN AALBORG. 

